Sprocket and chain construction



1934- T. s. MILLER ET AL 1,970,763

SPROCKET AND CHAIN CONSTRUCTION Original Filed May 1952 INVENTORS TS.MLLL9I" Look L 6770173 dwell. Chung '11 b'arn L. ('15 01W BY Q L}ATTORNEY- Patented Aug. 21, 1934 s'rrs iii i SPROCKET AND CHAINCONSTRUCTION Tony S. Miller, Look L. Chung, due L. Chong, and Sam L.Chung, Isleton, Calif.

1 Claim.

*This invention relates to agricultural implements and is particularly adivision of our copending application, Serial No. 611,840, filed May1'7, 1932.

: The agricultural implement to which this invention is appliedcomprises a rotary digging unit whose shaft is driven from its oppositeends by chains connected to a common drive shaft. One of the objects ofthis invention is to construct the sprocket wheels so that the opposedones of the same may be so initially set and adjusted rela-- tive toeach other as to positively and accurately equalize the pull on bothchains, and thus eliminate the possibility of the shafts or chains beingstrained by an unevenly distributed pull.

We also found that in this implement, in which the chains areunavoidably and constantly exposed to dirt, that sprockets of theordinary character soon became clogged with dirt between the teeth. Thiscaused the chains to gradually climb and tend to be crowded off thesprocket wheels so that said chains became unduly taut, ultimatelyresulting in the breakingof the same or some of the sprocket teeth.

A further object of this invention therefore is to construct thesprocket wheels so that they are self-cleaning and the tendency for themto clog up with dirt is eliminated.

A still further object is to construct the main driving sprocket wheelso that in the event of an unyielding obstruction being encountered bythe digging unit, certain relatively inexpensive and easily replacedparts will let go instead of the sprocket wheels and chains themselvesbeing probably fractured or broken.

A further object of the invention is to produce a simple and inexpensivedevice and yet one which will be exceedingly effective for the purposefor which it is designed.

These objects we accomplish by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claim.

In the drawing similar characters of reference indicate correspondingparts in the several views:

Fig. l is a top plan view of a rotary digging unit and chain drive meansapplied thereto.

Fig. 2 is a side view of one of the special sprocket wheels detached.

Fig. 3 is a diametral section of the wheel from the line 33 of Fig. 2.

Fig. 4 is a similar View of a double drive sprocket wheel and thespecial form of hub for the same and the connecting means therebetween.

Referring now more particularly to the characters of reference on thedrawing, the rotary digging unit comprises side frames 11 pivoted attheir forward ends in axial connection with the drive shaft 2 which isjournaled in boxes 3 supportedby the frame member 4 which is mountedon'the tractor and from which) the shaft 2 is driven J ournaled inconnection with the frames I 1 parallel to the shaft 2 is the shaft 5 ofthe rotary digging unit 6 which is of the same general character as thatshown in Patent No. 1,816,210, dated July 28, 1931, and others of a likenature.

- Sprocket wheels 7 are fixed on the outer ends, of the shaft 5 and arealined with similar sprocket wheels 8 mounted on the ends of the shaft2, with chains 9 between corresponding pairs of sprockets, as shown inFig. 1. One of the sprocket wheels 8 is in the form of a ring 10 whichis taper bored to engaged the similarly sloping edge of a circularflange 11 formed on a hub 12 which is keyed to the shaft 2. The sprocketwheel at the small end of its bore overhangs the adjacent side of theflange. A ring 13 is mounted on the hub V and abuts against saidoverhanging side of the sprocket wheel and is adjustably clamped to theflange by bolts 14; therethrough. In this manner when the bolts aretightened up the ring 13 is pulled toward the flange 11 and the sprocketwheel is wedgingly forced on to said flange so that it must turntherewith as a unit.

In this manner the said sprocket wheel may e initially adjusted and setrelative to the opposite one so that the pull on both chains may be 1accurately equalized, thus eliminating the possibility of either shaftbeing strained by an unevenly distributed pull.

The shaft 2 is driven from the power take-off shaft of the tractor by adouble chain drive unit which includes a double sprocket 15 on the shaft2. Said chain drive is as usual connected to the engine of the tractorwith a manually controlled clutch unit therebetween. The rotary diggeris thus driven by the rotation of the shaft 2. Since is digging bladessometimes strike a rigid obstruction underground which is apt to breakthe chain or other relatively weak and expensive part which cannotalways be replaced at short notice, we connect the sprocket 15 of thechain drive to the shaft 2 in such a manner that the easily carried inthe tool box of the tractor. H0

Said sprocket wheel is therefore mounted as follows:

Keyed on the shaft 2 is a sleeve or hub 16 having a flange 17 projectingoutwardly intermediate its ends. The double sprocket wheels are formedas a unit turnable on the flange and hub and have in common a ring-likeweb 18 which bears against the flange 17, so that the shear bolts 19 maybe placed'through the web and flange to hold the same together indriving rela-, tion.

All the sprocket wheelsare provided on both sides and between theirteeth at the bases of the same with curved inwardly extending recesses20. In this manner the sprocket wheels between the teeth are somewhatnarrower than the teeth themselves and the chain rollers which ridetherebetween. The area of contact of the faces of said chain rollers andthe sprocket wheels are so reduced at these points that the chances fordirt to become packed between the parts is minimized and any such dirtas may adhere to the wheels or chain rollers will be pushed into therecesses as the chain engages. the wheel and will drop clear'of thewheel. The latter is therefore selfcleaning and will not tend to clog upand pack with 'dirt as is the case with the ordinary form of sprocketwheel under similar working conditions.

From the foregoing description it will be readily seen that we haveproduced such a device as substantially fulfills the objects of theinvention as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from suchdetail maybe resorted to as do not form a departure from the spirit ofthe invention, as defined by the appended claim.

Having thus described our invention what we claim as "new and useful anddesire to secure by Letters Patent is:

A- means for adjusting the position of a gear relative to a shaftcomprising a hub fixed on the shaft, an annular flange projecting fromthe

